Okay guys, you are about to be exposed to my inner nerd, for better or worse...
In "The Lord of the Rings", Gandalf is the wizard protecting Frodo the Hobbit and his company of adventurers. While traversing the abandoned Mines of Moria, the group is confronted by the demon Balrog. Gandalf makes a last stand against the creature on a rocky bridge while the company makes it's getaway, famously saying to the demon "You shall not pass" before falling with it into the subterranean abyss...
Edit: BP beat me to it. That's the curse of being old and typing REALLY slow...